


Breaking Boundaries

by LaughingGaster666



Series: Four universes [4]
Category: Undertale (Video Game)
Genre: Anal Sex, Bad Puns, Blow Jobs, Cock Slut, Ecto-Penis (Undertale), Explicit Sexual Content, Fluff and Humor, Fluff and Smut, Foreskin Play, Gay Sex, Gratuitous Smut, Loss of Virginity, M/M, Oral Sex, Other Ships Not Mentioned in Tags, Penis Size, Porn With Plot, Porn with Feelings, Puns & Word Play, Romance, Rough Sex, Sexual Humor
Language: English
Status: Completed
Published: 2019-05-19
Updated: 2019-12-26
Packaged: 2020-03-08 01:26:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 5,485
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18885322
Author URL: https://archiveofourown.org/users/LaughingGaster666/pseuds/LaughingGaster666
Summary: After the Swapfell brothers agreed to date each other, there is only one thing left to do to make it official. Morto (Swapfell Papyrus) is nervous. Diablo (Swapfell Sans) isn't. He should be.





	1. A very good question

**Author's Note:**

> Nickname guide for new readers:
> 
> Undertale Sans - Cloud  
> Undertale Papyrus - Phoenix  
> Underswap Sans - Sapphire  
> Underswap Papyrus - Citrine  
> Underfell Sans - Saturn  
> Underfell Papyrus - Mars  
> Swapfell Sans - Diablo  
> Swapfell Papyrus - Morto

_Two weeks after the events of Now they’re dating in the Multiverse… at the Grillby’s in the Undertale Universe…_

 

“so, have you two done it yet?” Citrine asked.

 

Morto choked a bit on his caramel whiskey. “... did you seriously wait until i was drinking to ask that question?” Morto replied with an ‘are you serious’ look to match.

 

Citrine smirked while giving an innocent shrug in response. “you know, for a pervert, you sure clam up a lot whenever sex comes up.”

 

“only when it involves diablo too.” Morto quipped back.

 

“want another drink?” Cloud asked as he walked down to the corner of the bar Morto and Citrine were at.

 

“sure. alexander for me.” Citrine said.

 

“just another glass of caramel whiskey on the rocks cloud.” Morto said.

 

Cloud went off to make the drinks and the two tall skeletons returned to their conversation.

 

“... but seriously, when are you going to ask him about it? you do realize that your guy is a bit… lacking in the knowledge department on the subject of sex right?” Citrine pointed out, much to the displeasure of Morto.

 

Morto cringed. “all the more reason to take my time with it. i don’t want him to feel pressured into it. we’ve only been on 3 dates so far.” Morto justified.

 

“so your plan is to just wait for him to initiate the sexy times then? the guy who i’m pretty sure doesn’t have a sexual bone in his body?”

 

Morto would laugh at the pun, but now wasn’t the time.

 

Morto was about to reply but Cloud interrupted with their drinks. “alexander for citrine, and a caramel whiskey on the rocks for morto.”

 

“thanks cloud.” “thanks man.”

 

Cloud turned to leave but before he stepped away to attend to the other customers, he whispered to the two skeletons “if you think that a guy who’s friends with saturn, sapphire, and mars is ignorant about sex, you’ve got another thing coming.”

 

“Now that i think about it, sapphire mentioned something about saturn showing diablo some porn he made the day they met to show him what sex was…”

 

It was at this moment that Morto remembered that Diablo had gone to hang out with Sapphire and Saturn tonight.

 

“crap. i have a feeling that saturn is going to convince diablo to do some weird shit again. ughhhhh.” Morto groaned.

 

“to be fair, you being passive all the time isn’t exactly helping things. it was what drove him to those two clowns after all.” Citrine reminded him.

 

Morto gave a groan signifying that he was probably right but he wasn’t going to flat out say it as he took a sip.

 

“still, i just want his first time to be… natural you know? i want it to be what he wants, not what i or anyone else insist on.” Morto lamented.

 

“we both know first times rarely go very well anyway.” Citrine shifted slightly in his seat. “for a guy who knows how to fuck hard and fuck well, you’re such a hopeless romantic sometimes i swear.” Citrine chuckled a bit.

 

“aren’t you single right now?” Morto reminded him with an evil grin.

 

“you’re a dick man. you know that right?”

 

Morto moved his head in to whisper “a big huge throbbing dick. that’s right.”

 

Oh snap. That was enough to make Citrine blush beet-red before mumbling something incoherent about bipolar people.

 

Both of them silently sipped their drinks before cloud asked if they were thirsty for more.

 

“nah, gonna just head back to swapfell i think. thanks for the chat though citrine. you were right about one thing at least.” Morto said before he paid and left the bar.

 

“what were you right about?” Cloud asked Citrine as he cleaned up after Morto.

 

“not sure. i swear, sometimes i feel like i can read that guy like a book, but he changes languages everytime i open the book.” Citrine shook his head.

 

Cloud gave a slight nod in agreement. “oh, by the way, i noticed that icewolf was checking you out for the past 10 minutes, and had a grin on his face when morto left. use this information however you want to.”

 

As Citrine contemplated whether he wanted to try and get lucky tonight, Morto was rethinking whether he really should just let Diablo take things at his own pace. Did waiting on Diablo really put less pressure on the guy? Not to mention there’s a good chance Diablo wants to do it but just doesn’t feel sure as to how he wants to initiate it. And if he doesn’t know that, then he’s probably going to ask his friends what he should do. Friends that are very much on the amorous side of things.

 

‘you know what? i’ll go home, and talk to diablo about this like a mature adult. He did want to be treated as one after all, so he will get what he’s wanted. then we can do it whenever and finally share a bed! the two of us don’t have any reason to feel lonely when we wake up anymore.’ and with that thought, morto smiled to himself, happy at his decision.

 

After a phone call, a grey door trip to his neighborhood, and a short walk Morto was at his house. He could have teleported, but he was a tad tipsy from the drinking earlier. It’s a good thing he didn’t, since he found something strange on the door to his house.

 

It was a note in his brother’s handwriting that said: “WARNING! THIS IS THE BONE ZONE! ENTER AT YOUR OWN RISK!”

 

Morto wasn’t sure whether to laugh or run away. Usually, whenever his brother made a pun, it was a setup to distract him, either to get him to give something up, or to smack him for whatever he had done to tick Diablo off that day. Taking a deep breath, he opened the door.

 

He wasn’t really sure what he was expecting.

 

His brother was watching TV. Shirtless. And the program on the TV didn’t look very… appropriate to say the least. Wait… oh fuck! It’s porn! Wait, is that Saturn and Mars? It is! Fuck!

 

Before Morto could react, Diablo spoke up. “PAPY! SO GOOD OF YOU TO JOIN ME! WHY DON’T YOU TAKE A SEAT RIIIIIGHT HERE.” Diablo said with a smile that totally wasn’t hiding any malicious intent as he patted the couch cushion.

 

Surrendering, Morto let out a slight whimper as he complied. He underestimated his brother. Guess he really was going to make him the bitch in this relationship. Huh. That thought was scary… yet arousing. Fuck it. It’s not like he hadn’t fantasized about his bro fucking him like a desperate slut. Guess you really should be careful what you wished for.


	2. You reap when you're a slut

**Summary for the Chapter:**

> Sometimes, what went in your ass comes back to haunt your love life.

**Notes for the Chapter:**

> FINALLY, we get to some shameless smut in this. Not the kind you were expecting though.

The two skeletons cuddled a bit as they watched the TV. That didn’t stop Morto from being nervous as fuck as they watched Saturn railing Mars. Morto wasn’t sure, but he was starting to think that this was Diablo’s way of asking if he was okay with bottoming.

 

At this point in the scene, Saturn was thrusting almost his entire dick in and out of Mars. They were doing it doggy style and Mars had taken it upon himself to bite onto his brother's shoulder and dig his claws into his bones for additional leverage.

 

“DAMN. THEY’RE REALLY INTO IT AREN’T THEY?” Diablo said with a somewhat amused expression.

 

“y-yeah. they’re certainly enjoying themselves.”

 

“HONESTLY, IT REMINDS ME OF YOU IN SOME OF YOUR VIDEOS.” Diablo deadpanned.

 

After recovering from his moment of shock, Morto asked “w-what do you mean? i’ve never made any videos like this!”

 

“GUESS THEY DIDN’T TELL YOU THEN. I’LL LET YOU FIGURE IT OUT ON YOUR OWN AS WE WATCH.” Diablo said as he stopped the current video and put on the next.

 

It was a video of Morto, surrounded by Doggo, Dogamy, Greater Dog, and Lesser Dog.

 

Morto’s eyes popped out. Just how the hell did Diablo find this? They promised that their sexual activities were not going on the internet! He was going to fucking destroy those mutts later.

 

“Is it on sweetie?” Dogamy asked. Dogaressa was usually the one that filmed the guys when they did this. She liked to watch them all fuck anyway.

 

Dogaressa gave a thumbs up in the corner of the camera view.

 

“So, whose turn is it?” Doggo asked.

 

“I distinctly remember that it’s been a while since you’ve been fucked like a bitch. no offense dogaressa.” Morto answered.

 

Dogamy gave him a glare but didn’t say anything.

 

Doggo growled. “It’s been even longer since you’ve been fucked bone boy.”

 

Greater and Lesser Dog gave a woof of agreement.

 

Morto put up his hands in surrender. “alright, ya caught me. i guess i’ll take one for the team then.”

 

“I don’t think it counts as ‘taking one for the team’ when you’re more of a needy bitch in heat than my wife.” Dogamy piped in.

 

“Are you saying I’m not good enough honey?” Dogaressa interrupted in a sweet voice. The camera view couldn’t show it, but Morto remembered seeing a sweet expression on her that was most certainly masking some serious bloodlust.

 

“O-Of course not sweetie!” Dogamy said nervously as the others snickered.

 

“better watch your mouth man, or she’ll put you in the doghouse.” Morto commented slyly.

 

“Doggo.” Dogamy deadpanned.

 

“Yes sir?” Doggo leaned forward, with a knowing look on his face.

 

“Can you make Papyrus shut up a little bit please?” 

 

“With pleasure!” And with that, Doggo dropped his pants, grabbed Papyrus, and pushed him onto his half-hard dick.

 

“I must say, Papyrus’s mouth is a lot better when he isn’t talking~” Doggo said in between breaths, clearly enjoying being sucked off.

 

Greater and Lesser Dog gave a yip in agreement.

 

“Hey now, don’t get too comfortable. After all, sharing is caring!” Dogamy said as he chucked off his cloak and pants, showing off his own hard canine cock now.

 

Following his lead, Doggo pulled his shirt off while Lesser and Greater Dog got out of their armor. 

 

When you need to satisfy 4 horny dogs, foreplay kinda goes out the window. Which is more or less what happened when Doggo shoved Papyrus off his dick and practically ripped his clothes off before shoving him on the bed.

 

“such manhandling.” was all Papyrus said, as if he was protesting as weakly as possible.

 

“Oh quit your whining and open your ass up. Lesser wants a taste.”

 

Putting his bony hands over his now magic ass to spread his cheeks, Papyrus didn’t have to wait long before he felt a tongue slide in. As Papyrus let out a short gasp, Greater swooped in on the opportunity to shove in his own dick into Papyrus’s mouth.

 

“Nice steal Greater!” Dogaressa encouraged.

 

“Hey! Whose side are you on!” Dogamy complained in turn, clearly annoyed he hadn’t been able to get his dick wet yet.

 

“Probably the one where you get fucked like a bitch, but that’s not important right now.” Doggo answered as he repositioned himself. “That’s enough rimming I think Lesser. Let’s get ready to fuck him now. Oh yeah, and could you pull up your full body now Papyrus? Lesser and Greater want to manhandle you and your bones are a bit slippery with all of us trying to fuck you.”

 

It was honestly a bit comical how quickly Papyrus snapped his fingers while sucking off Greater to have his full ecto-body cover everything below his neck. He always felt a bit embarrassed when he pulled it out since he had a bit of a beer gut with it, but the guys liked it when he did it. Something about having ‘meat on his bones’ made them feel like they weren’t fucking a literal pile of bones. Which… made it seem like they were missing the whole point of fucking a skeleton really. Skeletons are supposed to be thin, not thick. Then again, the guys also loved his bare bones when they felt like biting him, but they didn’t want to get _that_ rough with him today.

 

At this point the four males crowded around Papyrus, making it a bit hard to tell who was doing what now as the camera zoomed in on him. The bottom is always the star in a gangbang after all.

 

Someone put their dick in his ass, followed by a dick in his mouth when he cried out from a bit of pain and pleasure mixed together. Then another dick crammed into his already stuffed hole, prompting his eyeballs to pop out along with a few tears. It clearly was hurting him, but it felt too good to stop at the same time. Then a paw dragged an ecto hand to a canine cock, prompting Papyrus to give a sloppy handjob while he was dealing with 3 dicks in him at the same time.

 

Papyrus in the present day noticed he was now hard, glowing, and- OH FUCK WHY IS SANS’S HAND ON HIS CROTCH!?!

 

“WOW YOU MUST REALLY BE ENJOYING THIS HUH? YOU’RE ALREADY HARD AS A ROCK MONSTER.” Sans slyly commented, refusing to break his glare at the TV.

 

Fuck when did Sans become an expert at teasing him? Ugh, Saturn probably tutored him in this crap.

 

Back on the TV, Papyrus had now given up the handjob and blowjob, instead giving a “eyejob” to two canine dicks now. In and out, two dicks in his ass, one in each eye socket. All the while, Dogamy and Doggo were encouraging him, with comments including, but not limited to: “Fuck yeah slut your ass is good.” “Hell yeah man I love it when you’re the bitch in heat for us.” “I wonder what your brother would think if he saw us? Heh, little pup would probably be devastated to know his big protector was a huge slut that can’t resist the opportunity of getting fucked long and hard.”

 

That last comment caused Sans to stop the video. “OKAY, I WAS PLANNING ON MAKING YOU WATCH THE WHOLE THING, BUT YOU KNOW WHAT? NOW I CAN’T WAIT TO FUCK YOU LIKE THEY DID YEARS AGO. COME ON!”

 

And before Papyrus knew what Sans was doing, he found himself scooped up by his brother, who had now scooped him up and had his own ecto-body out and… ooooooh man his brother had a nice ecto-body. Good arms, well-developed pecs, and a nice six-pack. He didn’t have the shining armor, but he really had the handsome knight thing going for him. No wonder he went shirtless for this.

  
Sans quickly carried Papyrus up the stairs to his bedroom before tossing Papyrus on the bed. With a lecherous grin, he spoke: “NOW, THE _REAL_ FUN BEGINS!”

**Notes for the Chapter:**

> You thought it would be Sans fucking Papyrus in this chapter. BUT IT WAS I! DOGGO!
> 
> Side note: Why aren't there more stories with Papyrus and/or Sans with the dogs? Bones and dogs are kind of known to go together people!


	3. The REAL sex begins!

**Summary for the Chapter:**

> Sex. The kind you actually clicked on this story for, probably.

Sans was quick to pounce on Papyrus, hopping onto the bed before pinning him down as he roughly kissed him. Papyrus was still in shock at how quick all of this was happening. He wanted to tell Sans to slow the fuck down and that he was getting overwhelmed from everything but it was too hot for him to say anything and it just felt  _ so right _ when his brother kissed him roughly like that!

 

Papyrus did notice that Sans was a tad distracted as he attempted to take off Papyrus’s jacket. Eventually Sans broke the kiss off with a frustrated groan to tell Papyrus to get up so he could get the clothes off already.

 

Papyrus chuckled before giving a “sure bro” followed by chucking the fluffy jacket to the floor along with his orange tank top he wore under it today. Sans was clearly very eager, but the lack of experience was being put on display right now.

 

Papyrus then saw Sans look at him expectantly, as if there was something else he had to do.

 

“ECTO-BODY YOU BONEHEAD. SHOW IT TO ME!”

 

Papyrus resisted the urge to laugh at his brother’s pun as he snapped his fingers, letting the orange magic cover his body now.

 

Looking down, he remembered why he was a bit shy to pull this part of him out much. He had a bit of a beer gut in this form. Then again, going to Muffett’s diner all the time would do that to anybody. Heh. Any “body”.

 

His train of thought was broken by Sans touching said beer gut with two hands covered in blue magic.

 

“... YOUR BELLY IS CUTE.” Sans said as he continued exploring his body, gently pushing Papyrus down on his back again. Papyrus was pretty sure he was blushing now and didn’t dare speak as he didn’t trust himself to not squeal or moan if he tried to say something.

 

The two kissed as Sans groped him, prompting Papyrus to get a bit grabby himself. It didn’t take him long to appreciate Sans’s ecto-body now. God, those fucking abs were just as amazing to touch as they were to look at.

 

Getting a bit more aggressive now, Papyrus flipped over, pushing Sans on his back now. Sans was a bit startled but didn’t make a move to try and stop it. Papyrus’s hands drifted now, Sans’s abs were grade A stuff, but his pecs could not be ignored either. Experimentally, Papyrus rubbed at one of the nipples to see if there was a reaction. A small moan from Sans was a sign that his brother did indeed have sensitive nipples. Yeah, ecto-bodies were cool.

 

Papyrus broke off from kissing to give the nipple a few licks. Sans seemed to enjoy it so he kept going at it, eventually giving a small bite.

 

“AGH~ FUCK. DON’T STOP WHATEVER YOU’RE DOING PAPYRUS.” Sans encouraged.

 

Papyrus then felt bold enough to start twisting the other nipple with his free hand as he bit down on the other. Hard. Sans was losing it and Papyrus loved it. They hadn’t even taken their pants off yet!

 

“OKAY THAT’S ENOUGH FOREPLAY I THINK. WHAT YOU’RE DOING WITH YOUR MOUTH IS GREAT AND ALL BUT THERE ARE OTHER THINGS IT SHOULD BE USED FOR.” Sans said as he gently pulled off Papyrus from biting him now.

 

“aw, your moans were so cute though.” Papyrus said in mock disappointment.

 

“OH PUT A DICK IN IT.” Sans said before shoving Papyrus’s face to his crotch. Clearly, getting on Sans’s nerves was a surefire way to make him forget about being gentle and lovey dovey during sex.

 

Papyrus gave a short chuckle as he undressed Sans. Skull belt came undone first, black pants were unzipped, revealing a fairly well endowed hard dark blue cock leaking a bit of pre. Chucking Sans’s pants to the floor, Papyrus got a nice look at it before giving a quick lick. Around 6.5 inches in girth and length if he had to guess, and he appreciated every inch.

 

\-------------------------------------------------------------------------------------------------------------------

And now I get to describe Diablo’s dick in excruciating detail! Since it’s basically a rule that every Sans has a big girth for the ones who get big dicks, that’s what I went with here. Diablo isn’t as strong as his brother when it comes to magic, but since he works out and trains constantly and ecto-bodies are related to physical characteristics, he still is packing decent heat under his waist.

Note: This also means that the lazy skeletons would be goddamn MONSTROUS in default proportions if they worked out like their bros did. If I ever make a story with a “bara” Undertale or Underfell Sans for example, they’d be fucking crazy in proportions. The good news is that skeletons can “adjust” their size a bit with some concentration as it is magic technically, but since Morto didn’t need to do that when he was fucking Citrine, it hasn’t really came up in the story yet.

“heh. you said came and we’re talking about gay sex.” Morto interrupted with a chuckle.

Shut the fuck up bone boy, or you’re getting gangbanged by horrortale sans, error sans, dusttale sans, and every other version of him that’s a deranged murderous psycho that doesn’t really know how to not be rough when they fuck to the point where first aid kits are used by their partners post-sex on a regular basis. They like to use blood as lube by the way.

“...” Morto said.

\-------------------------------------------------------------------------------------------------------------------

 

Papyrus’s tongue slid up and down the shaft a few times before he put it in his mouth. Bobbing his skull a bit, he starting sucking away.

 

“GAH~ FUCK THAT’S GOOD PAPYRUS.” Sans encouraged as he gripped the bed sheets tightly.

 

Taking this as his cue to go faster, Papyrus picked up the pace a bit. Sans was moaning softly at this point. Papyrus slowed down a bit and made sure his tongue was hitting all the right places, getting in a few licks to play with the foreskin. It makes him go crazy when other people do it, so he guessed that it makes Sans go crazy too when he does it.

 

“FUCK YEAH KEEP DOING THAT! THAT’S THE SPOT!”

 

Looks like he guessed correctly. Getting his tongue all around the sweet spots was driving him crazy too. Then he wondered if Sans liked being deepthroated. It made absolutely no sense how skeletons could do it, but he did it anyway.

 

“WAIT! STOP! I DON’T WANT TO CUM YET!”

 

Slightly annoyed but a bit glad that his brother didn’t cum without a warning at least, Papyrus spat the big blue dick out with a “pweh” noise.

 

“I WANTED TO FUCK YOU AND CUM IN YOUR ASS, ASSUMING YOU’RE OKAY WITH THAT.” Sans answered the questioning look Papyrus was giving him.

 

Papyrus gave a short chuckle in response. “sure, it’s your first time after all. whatever you want bro. do you have lube?”

 

“OF COURSE I DO! LORD SANS ALWAYS PLANS AHEAD!” Sans said as he turned around to reach into his nightstand to grab the lube.

 

Sans’s very nice blue bubble butt was on full display as he did this. Papyrus then had a lecherous thought that would almost surely get Sans angry if he acted upon it. Then again, angry sex was sometimes really good, and the opportunity was presenting itself.

 

Whatever. His brother basically ambushed him with this. He should get his comeuppance.

 

And with that, he gave Sans’s ass a big smack with his left hand.

**Notes for the Chapter:**

> Wow Papyrus. You're playing with fire and Grillby isn't even around. Impressive.


	4. You get what you ask for

**Summary for the Chapter:**

> When you play with fire in bed, don't be surprised when things get hot and heavy.

**Notes for the Chapter:**

> Why did this take so long? Waaaaaaay too much has been happening in the past few months. Going to school on top of having a job full time is no fun, I'll tell you that. Regardless, the end result I believe is one of my best chapters in a while. I hope you all enjoy.

Sans gave a short, muted yelp as he froze in reaction to the sudden spank he received.

 

Papyrus didn’t really know what to follow up with. Clearly, he had not thought this through, and Sans was not moving.

 

“um... sorry?” he said, hoping that he didn’t screw it all up.

 

Papyrus cautiously moved his hand to put on Sans’s shoulder, only for Sans to go from frozen and looking away to spinning around, grabbing his wrist, flipping him over on the bed again, then finishing with a rough kiss, teeth scraping Papyrus’s tongue.

 

“YOU ASKED FOR THIS.” was the only explanation Papyrus was getting as he found himself gagged with the red scarf he had given to Sans years ago.

 

“SINCE YOU ARE… UNABLE TO USE SAFE WORDS RIGHT NOW, JUST TAP YOUR HAND THREE TIMES IN A ROW ON THE BED IF YOU NEED ME TO STOP. GOT IT?”

 

Realization coming through, Papyrus nodded. In the back of his mind, he  _ was _ looking forward to this. After all, he did just spank his brother unexpectedly. He was sort of going for this kind of response, even if he didn’t explicitly ask for it.

 

“LIE DOWN.”

 

Papyrus did as he was told, face down now. He thought about wiggling his ass suggestively but he thought he should probably just wait and see what Sans is planning for now.

 

Papyrus could hear a squirt sound then felt a wet finger enter his butt without much warning.

 

‘oh, he’s lubing me up. duh.’ he thought to himself.

 

After about a minute or so of the lubing up, Sans removed his finger. Papyrus could hear another squirt, probably Sans lubing his dick up now.

 

Papyrus was right again but didn’t have much time to think about that since his  _ ass was getting FUCKING DESTROYED now Oh mY god JESUS Fuck Sans TOO HARD ah fuck _ ahhhhhh.

 

Whimpering through the pain, Papyrus considered tapping out now. Oh damn it hurt. It really fucking hurt. Yet he loved it so, so much. God, he was such a whiny little bitch sometimes.

 

‘Thrust’ “ENJOYING YOURSELF MUTT?” Sans quipped as he thrusted vigorously. Papyrus couldn’t see, but he was fully confident his brother was grinning sadistically as he sodomized him.

 

Papyrus was then jolted by a smack on the butt. “ANSWER WHEN I’M TALKING TO YOU! IT’S A SIMPLE YES OR NO QUESTION. YOU CAN NOD OR SHAKE THAT EMPTY SKULL OF YOURS!”

 

Papyrus quickly nodded to acknowledge the fact that he was indeed enjoying this rough romping session now.

 

“THAT’S TOO BAD.” Sans stated, and in a split second, he stopped thrusting entirely. He wasn’t even  _ moving _ at all!

 

“DON’T MOVE.” Sans said before Papyrus got any ideas. Sans even put blue magic on Papyrus’s soul to bind him.

 

Papyrus was losing his mind right now.  _ Just right when he’d started adjusting to the fast _ , rough pace of his brother’s thrusts, he just  _ stops _ entirely!

 

“TAKE THE GAG OUT. NO MOVING YOUR HANDS THOUGH.” Sans ordered.

 

Oh now this was just cruel. Papyrus was already a bit choked up from the rough sex, but making him struggle to spit out a gag while there was a big fat dick in him was tearing him apart right now.

 

He still loved it though. So far, this night was proving that he loved it when his brother got hard and rough with him. He loved it far, far too much really. Papyrus considered himself more of a versatile top, but Sans was quickly making him flip to being a complete and utter submissive little worshipper to his cock. And this was just how felt during their first time having sex. Oh man, he’d probably go so deep in the kinds of kinks possible if Sans asked him to do something crazy now.

 

Breaking his mind from that thought was him finally spitting that stupid gag out.

 

“GOOD JOB. HERE’S YOUR REWARD MUTT.” Sans said before quickly shifting gears from speed zero to speed turbo, making Papyrus grunt in pain once again.

 

After a while, the grunts of pain turned into soft moans.

 

“SOMEONE’S ENJOYING THEMSELVES.” Sans said with a chuckle between thrusts, briefly putting a hand on Papyrus’s now raging hard cock of his own, prompting a blush from Papyrus. “DON’T MIND ME, FEEL FREE TO GET AS LOUD AS YOU WANT.” Sans continued, almost trying to sound coy now.

 

Papyrus let his moans get louder. Sans found that he liked the sound of them. “SPEAK, TELL ME JUST HOW YOU FEEL.”

 

“ah- like i’m about to burst, but it feels  _ so good  _ even though it hurts so much and you make me feel so vulnerable but it’s so good because it’s with you and-” Sans cut him off with a deep thrust. “oh  _ fuck _ you’re driving me crazy right now agh! you’re relentless, that fucking dick of yours is too damn big gah!”

 

“ARE YOU CLOSE YET?” Sans asked.

 

“ugh yeah.” Papyrus gave another grunt in pain and pleasure mixed together. “You?”

 

“SAME. WHICH IS WHY I NEED A QUICK BREAK. AGAIN.”

 

“wait-” but there was nothing Papyrus could do about the fact that Sans had already stopped thrusting immediately, leaving him helpless as he couldn’t move either to satisfy his desperate need to have the throbbing cock in him to FUCK HIM ALREADY!

 

Papyrus whined in desperation as he waited in agony for his brother to stop torturing him and finish this already.

 

“BEG.” Sans ordered.

 

“wha-” “I SAID BEG YOU STUPID MUTT! DON’T YOU WANT IT? I THOUGHT YOU WERE ENJOYING THIS. IF NOT, I CAN JUST PULL OUT AND LEAVE YOU HERE, UNSATISFIED AND DESPERATE FOR SOMETHING YOU CAN’T HAVE.” Sans said in a rough yet teasing tone.

 

“n-no i want it! badly! fuck, i need you to cum inside me sans! please! you feel so good! i love you!”

 

‘Oh yeah, I forgot, he’d been bottling up his love for me for a while. No wonder he’s going crazy.’ Sans thought before speaking again “OH ALRIGHT, I SUPPOSE I’LL INDULGE YOU A BIT MORE.”

 

And thus the thrusting commenced once again. Now, Sans wasn’t holding back at all, this time going all the way in and almost all the way out with each thrust, and at a speed that should most certainly not be used on guys inexperienced with bottoming. But the pain was part of what made it feel so good on top of the normal pleasure Papyrus received from it, deriving intense feelings of masochistic urges from him. Psychologically, he just couldn’t help but go mad with lust at the fact that his brother was going all out right now. 

 

“I’M CUMMING!” Sans said, and lo and behold, he came quite a bit.

 

Both brothers were panting and sweating heavily, as they had both been putting in a big effort for this.

 

With a bit of a struggle, Sans pulled out, this time trying to be gentle for once. It was fairly easy for his deflated cock to exit the now expanded anus.

 

“OH WOW, I DIDN’T THINK I’D CUM THAT MUCH.” Sans said, slightly embarrassed but also a bit proud of himself.

 

“did you cream pie me? i can’t tell, i think that i’m going a bit numb now.” Papyrus said, now getting out of sub bitch mode and going into ‘oh dear god how did i take that much punishment fuck my abused ass is sore now’ mode.

 

“YEAH, IT’S LEAKING OUT OF YOUR BUTT BIG TIME. HUH. SO THAT’S WHAT BLUE LEAKING OUT OF ORANGE LOOKS LIKE.” 

 

“righteous.” was all Papyrus could reply with.

 

Sans flopped down next to him. “ARE YOU OK? I KNEW YOU LIKED IT HARD AND HEAVY BUT I WASN’T TOO ROUGH RIGHT?”

 

“no! no you were fine. i liked it, really. yeah it was pretty intense but i’m really glad we can do this stuff now.”

 

“GOOD.”

 

There was a moment of silence as the two let everything sink in.

 

“could you let go of my soul by the way? i can’t move much with it being weighed down.”

 

“OH RIGHT SORRY.” Sans said with a quick wave to let go of Papyrus’s soul.

 

“ah~ that’s better.” Papyrus said as he flipped on to his back. It was at this moment where both he and sans realized that his throbbing dick needed some attention as he hadn’t cummed yet.

 

“could you give me a brojob?” Papyrus said with a wink. Sans rolled his eyes at the awful pun but complied. After the pounding he just gave Papyrus, Sans was willing to tolerate it.

 

It didn’t take long for Sans to finish off Papyrus. “gah~” Papyrus grunted as he came. Like Sans, the volume was also fairly impressive. “thanks. phew. man i was pent up.”

 

“AS WAS I. CUDDLE WITH ME WILL YOU? IT’LL MAKE ME FEEL BETTER ABOUT TREATING YOU LIKE A DUMB DOG FIVE MINUTES AGO.”

 

And so they cuddled. Eventually, it ended up with Sans on top of Papyrus’s ribs. Many kisses were given to each other. All of it was indeed a necessity after the intense session of pure, unadulterated fucking they just finished having.

 

“hey now don’t feel bad. really, it’s completely normal for doms to be concerned about their subs afterwards, especially after the first time.”

 

“GOOD.”

 

Another pause. “AND PAPYRUS?”   
  


“Yeah?”

 

“I LOVE YOU TOO. I DON’T KNOW WHAT I’D DO WITHOUT YOU.”

 

“and i love you. good night”

 

“GOOD NIGHT. AND UM… PAPYRUS? SOMETIME… COULD YOU FUCK ME?” Sans asked, trying not to show how badly he wanted it.

 

Another dumb thought occurred to Papyrus, since the last one worked out so well, he decided to let this one go too.

 

Grabbing then pining Sans’s wrists to the bed, Papyrus then lowered his head to whisper “ready for round two m’lord?”

 

Sans then gulped. “UH… SORRY BUT COULD YOU GO A BIT EASY ON ME? AND NOT NOW? IT WILL BE MY FIRST TIME AFTER ALL.”

 

Papyrus gave a chuckle in response as he released his brother’s wrists. “whatever you want bro. but for now, bed.”

 

The two then settled back down into bed.

 

“SPOON ME.” Sans said, barely above a whisper.

 

“of course m’lord.” Papyrus replied in compliance as he wrapped his arms around his little brother.

 

While Papyrus would normally appreciate the irony in this cuddling position considering the fact that he was the one being the glorified fleshlight a few minutes ago, he was too tired to care as he closed his eyes and felt the warmth of his lover as he slept peacefully.

**Notes for the Chapter:**

> And that's it!
> 
> I think that next time, if there is a next time with these guys anyway, I'll try and plan out the story structure a bit more, and possibly just do the whole thing in one shot if it's short enough. I do enjoy doing this for you guys, but regrettably, my life doesn't give me a lot of time for this kind of thing regrettably.
> 
> While I don't normally take requests, I would like some input. Is there any direction or focus any of you would like to see the next story be about?


End file.
